Symbol display device for game machine

ABSTRACT

A symbol display device includes a stepping motor, a drive gear attached to a drive shaft of the stepping motor, a reduction gear meshing with the drive gear, and a reel fixed to the reduction gear. The stepping motor, the drive gear and the reduction gear are contained in the housing disposed in the reel. As a pitch radius of the reduction gear is set so as to be larger than that of the drive gear, a velocity of rotation of the reduction gear is lower than that of the drive gear. The stepping motor causes to rotate the reel with reduction of the rotational velocity.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a symbol display device for a game machine, such as a pachinko machine, a slot machine and the like, and more particularly to an symbol display device for driving a stepping motor to rotate a reel whose periphery symbols are arranged on.

[0003] 2. Description Related to the Prior Art

[0004] In a pachinko machine and a slot machine is well used a symbol display device having three reels whose periphery plural types of symbols are arranged on. In the symbol display device, each of the reels is attached to a drive shaft of a stepping motor.

[0005] In the pachinko machine, a ball enter in a start pocket, three reels start rotating, and thereafter automatically stop. Thereby, if symbols arranged on a judgment line form a winning combination, an attacker is opened for a predetermined time length. As the ball easily enters in the attacker, a player obtains many prize balls.

[0006] In the slot machine, after inserting several coins or tokens therein, the player operates a start lever to rotate the reels. When the player depresses a stop button, or the reels stop automatically. If symbols arranged on a judgment line form a winning combination, the player obtains many coins or tokens.

[0007] The pachinko machine or the slot machine is provided with a controller which controls a stopping position of the reels in order to arrange the same symbols on the judgment line at a predetermined probability. When the symbol display device drives, an inner lottery is made by using a random number generator, and the drive of the motor is controlled to fill the result of the lot. Accordingly, as the motor for driving the reel in the symbol display device, a stepping motor is used for easy controlling the stop position. The position of the reel is adjusted based on the number of the drive pulse supplied for the stepping motor.

[0008] Receiving a pulse signal, the stepping motor rotates a drive shaft attached thereto at a predetermined angle (thereafter unit-step angle). When receiving another pulse signal thereafter, the motor continues to rotate the drive shaft at the unit-step angle.

[0009] Just before the reel is stopped, a velocity of rotation of the stepping motor is made lower. In the stepping motor, when the unit stepping angle is larger, a time for the rotation at the unit step angle becomes longer. In this case, a difference of the rotational velocities between just before and after accepting the pulse signal is large, and the player can acknowledge that the reel does not smoothly spin and often finds it unnatural.

[0010] The problem will be solved when in the stepping motor the unit step angle is short. However, such a stepping motor is large and expensive as a reduction gear device is built in, and therefore hardly used in the symbol display device for the pachinko machine.

[0011] Further, Japanese Patent Laid-Open Publication No. 2001-224773 discloses an symbol display device in which a reduction gear having a large gear portion and a small gear portion is used. In the symbol display device, the large gear portion mashes with a drive gear of the stepping motor, and the small gear portion meshes with a gear attached through a shaft to a reel. The velocity of rotation becomes lower step by step, based on a ratio of pitch diameters between the drive gear and the large gear portion, between the large gear portion and the small gear portion, and between the small gear portion and the output gear. However, in this symbol display device, a wide space is necessary between the stepping motor and the reel for containing both of the large and small gear portions in the reduction gear. Therefore, the symbol display device hardly becomes thinner. Further, as many parts are used for producing the symbol display device, the cost for the production is high.

SUMMARY OF THE INVENTION

[0012] An object of the present invention is to provide a symbol display device which is thinner.

[0013] Another object of the present invention is to provide a symbol display device whose cost for the production is low.

[0014] Still another object of the present invention is to provide an symbol display device for which a small number of parts are necessary that is easily assembled.

[0015] In order to achieve the object and the other objects, an symbol display device of the present invention has a reduction rotational member to which is fixed a reel whose periphery several symbols are arranged on. The reduction rotational member is connected with a drive rotational member attached on a drive shaft of a stepping motor, and a diameter of the reduction rotational member is larger than that of the drive rotational member. The stepping motor, the reduction rotational member, and the drive rotational member are contained in a housing.

[0016] In an preferred embodiment of the present invention, each of the drive rotational member and the reduction rotational member are a gear. In another embodiment of the present invention, the drive rotational member is a small pulley and the reduction rotational member is a large pulley.

[0017] According to the invention, the symbol display device becomes thinner. Further, as it has a small number of parts, the cost for the production becomes lower.

BRIEF DISCRIPTION OF THE DRAWINGS

[0018] The above objects and advantages of the present invention will become easily understood by one of ordinary skill in the art when the following detailed description would be read in connection with the accompanying drawings:

[0019]FIG. 1 is a front view of a pachinko machine in which a symbol display device of the present invention is loaded;

[0020]FIG. 2 is a sectional exploded view of the symbol display device;

[0021]FIG. 3 is a cross-sectional view of the symbol display device;

[0022]FIG. 4 is a perspective view of a reduction gear;

[0023]FIG. 5 is a schematic diagram of a rotation transmitting mechanism;

[0024]FIG. 6 is a sectional exploded view of the second embodiment of the symbol display device;

[0025]FIG. 7 is a cross sectional view of the third embodiment of the symbol display device;

[0026]FIG. 8 is a cross sectional view of the forth embodiment of the symbol display device;

[0027]FIG. 8A is a plan view of a bearing supporter;

[0028]FIG. 9 is a cross sectional view of the fifth embodiment of the symbol display device.

PREFERRED EMBODIMENTS OF THE INVENTION

[0029] In FIG. 1, a pachinko machine 2 includes a playing surface 3, an symbol display device 5, a knob 11 a and a loading stage 11 b. On the playing surface 3, there are a passage 3 a, a window 3 b, a reel-start pocket 6, plural winning pockets 7, an attacker or open-close pocket 8, nails and pinwheels (not shown). Behind the reel-start pocket 6 and the plural winning pocket, the playing surface 3 has winning holes. Further, on the playing surface 3 are formed and a lost hole 9 and a special opening (not shown) which is opened and closed with the attacker 8.

[0030] The symbol display device 5 includes three reels 24 arranged one by one and is disposed behind the window 3 b. As there are various symbols on each of the reels 24, nine symbols appear from the window 3 b simultaneously. Note that the number of the reel may be also four and five.

[0031] In the loading stage 11 b, balls (not shown) are loaded by a player. When the player rotate the knob 11 in a counterclockwise direction, a shooting device (not shown) is driven to shoot each of the balls. The ball passes through a passage 3 a, and thereafter falls on the playing surface 3 to be captured by one of the reel-start pocket 6 and the winning pockets 7, or to enter in the lost hole 9. Further, when the attacker 8 opens the special winning opening, the ball may easily enter therein. The attacker 8, once it opens, is usually kept in open condition until the balls of a predetermined number (for example ten) enter in the special winning opening. Further, after the attacker is once closed, it opens again. The opening and closing the attacker 8 is repeated 16 times. When the ball enters in the winning holes or the special winning opening, 12 prize balls are supplied on the loading stage 11 b in accordance to one winning ball.

[0032] Especially, when the ball enters in the reel-start pocket 6, the symbol display device 5 is driven. The three reels simultaneously start spinning, and thereafter stops. If a winning combination of the three symbols appear horizontally or diagonally on a line, for example “7-7-7”, the attacker 8 opens the special winning opening.

[0033] In FIG. 2 illustrating a reel unit, the rotation transmitting mechanism 10 is attached to the reel 24. The rotation transmitting mechanism 10 is constructed of a stepping motor 13, a drive gear 15, a disc-like plate 16, a reduction gear 22 and a E-shaped ring 27. On the reduction gear 22, a rotational shaft 28, a disk portion 22 c and a light-shielding fragment 22 d are formed. The disk portion 22 c has a rectangular protuberance 22 a and a pillar-like protuberance 22 b and a screw hole 22 e. The drive gear 15 is a plain gear and attached to a drive shaft 14 of the stepping motor 13. The drive gear 15 is rotatably fitted in a hole 16 a formed in the disc-like plate 16 and meshes with an inner gear portion 22 f (see FIG. 5) of the reduction gear 22. In a center of the shaft holder disc 16, a bearing 17 is provided. In the shaft holder 17 the rotational shaft 28 is inserted. On an end of the rotational shaft 28, the E-shaped ring 27 is attached to keep the rotational shaft 28 in the bearing 17.

[0034] Between the rotating transmitting mechanism and the reel 24, there is a cover 23 in which an aperture 23 a is formed. In the aperture 23 a is inserted the disk portion 22 c of the reduction gear 22. A rectangular protuberance 22 a and a cylindrical protuberance 22 b of the disk portion 22 c are respectively fitted in holes 24 a and 24 b formed in a center of the reel 24. The difference of the shapes between the rectangular protuberance 22 a and the cylindrical protuberance 22 b makes the reel 24 may be attached in a correct position. Further, the reel 24 has a screw hole 24 c through which a screw 26 is inserted in a screw hole 22 e of the reduction gear 22 e such that the reel 24 may be fixed to the reduction gear 22.

[0035] The disk plate 16 has an opening 16 b for disposing a photo sensor 21 attached to a base plate 20. On a rear face (not shown) of the base plate 20, parts for the photo sensor are fixed. As the parts are set in the opening 16 b, edges of the rear face of the base plate 20 facially contact to the disk plate 16. Accordingly, the photo sensor 20 is disposed on the disk plate stably.

[0036] The photo sensor 21 includes a light projector and a light receiver (not shown). As shown in FIG. 3, the light-shielding fragment 22 d of the reduction gear 22 passes in the photo sensor 21, and thereby shields a detection light projected from the light projector to the light receiver. Corresponding thereto, the photo sensor 20 generates a reel home position signal to send it to a controller (not shown) of the pachinko machine 2. The controller controls the stepping motor 13 based on the reel home position signal, so as to control a stop position of the reel 24.

[0037] As the light-shielding fragment 22 d is provided not for the reel but for the reduction gear in order to detect the reel home position, the reel home position can be detect even when the reel 24 is removed. Further, the attachment of the dust on the sensor is prevented.

[0038] In FIG. 4, the reduction gear 22 has a cylindrical protrusion 22 g. On an inner surface of the cylindrical protrusion 22 g, an inner gear portion 22 f is formed. The number of tooth of the inner gear 22 f is larger than that of the drive gear 15. As shown in FIG. 5, a pitch diameter of the inner gear portion 22 f is larger than that of the drive gear 15. Therefore, while the inner gear portion 22 f meshes with the drive gear 15, the reduction gear 22 rotates more slowly than the drive gear 15. For example, supposed that the pitch diameter of the inner gear portion 22 f would be four times larger than that of the drive gear 15, the stepping motor 13 rotates the drive gear 15 four times for rotating the reduction gear 22 once. Accordingly, the reel 24 rotates at a smaller angle than the unit step angle of the drive shaft 14 of the stepping motor 13. Therefore, even when the reel 24 rotates slowly, the rotation of the reel is smoothly.

[0039] The assembling of the reel unit will be explained now. The stepping motor 13 is fixed in the case 12. on the stepping motor 13 is set the disk plate 16 to which the photo sensor 21 is attached, and thereby the drive gear 15 is inserted in the hole 16 a. The disc plate 16 is fixed in the case 12 by a screw (not shown). On the disc plate 16, the reduction gear 22 is superposed. Thereby, the inner gear 22 f is meshed with the drive gear 15, and the rotational shaft 28 is inserted in the bearing 17.the cover 23 is fixed to the case 12 so as to cover the reduction gear 22. The case 12 and the cover 23 construct a housing. The disk plate 22 c of the reduction gear 22 protrudes from the opening 23 a of the cover 23. After setting the reel 24 to the disc plate 22 c, the reel 24 is fixed to the screw 26. The housing is fixed to the frame of the pachinko machine. As the reel 24 is fixed to the reduction gear 23, the housing is not thick in a direction of the rotational shaft 28 so as to be contained in the reel 24.

[0040] The effect of the above pachinko machine will be described now. The player load the ball from the loading stage 11 b in the pachinko machine 2. When the player rotate the knob 11 a adequately in the clockwise direction, the balls pass through the passage 3 a and fall on the playing surface 3 one after another. When the ball enters in the winning hole through the reel-start pocket 6, each of the stepping motor 13 drives the three reels 24 to spin, and thereafter the reels 24 automatically stop spinning. The reel 24 stops in the reduction of the rotational velocity of the stepping motor 13. Thereby, before and after the stepping rotation of the stepping motor 13, the difference of the rotational speed of the reel 24 is small such that the rotational speed of the reel 24 is reduced smoothly. Therefore, the player does not feet the reel spins curiously.

[0041] A number of the drive pulses necessary for rotating the reel 24 once is calculated from the unit step angle of the stepping motor 13 and the ratio of the pitch diameters between the drive gear 15 and the inner gear portion 22 f. Accordingly, the controller can specify a rotational position of the reel 24 based on the number of the drive pulse supplied for the stepping motor 13 after receiving the reel home position signal. Furthermore, as the arrangement and the types of the symbols on the reel 24 is known based on the reel home position, the controller can also specify the types of the symbols which appear in the window 3 b. The controller stops the reel 24 to set the symbols specified in the lottery in the window 3 b. When the combination of the three symbols is a winning combination the attacker 8 opens, and the player can obtain the large number of balls.

[0042] In the embodiment above, the reduction gear 22 g has the rectangular protuberance 22 a and the pillar-like protuberance 22 b. However, the shape and the number of such protuberances used for fixing to the reel 24 are not restricted. Further, in order to fix the reel 24 with the screw 26, a washer may be used. When the types or the arrangement of the symbols may be varied, the reel 24 can be changed to another one.

[0043] The light-shielding fragment 22 d and the photo sensor 21 may be disposed in another positions different from embodiment shown in FIG. 3. Further, the photo sensor 21 may be a reflection type.

[0044] In the second embodiment of the present invention, as shown in FIG. 6, a stepping motor 30 and a case 32 are used, and the reduction gear 22 g has a rotational shaft 29 which is longer than the rotational shaft 28 illustrated in FIG. 4. The rotational shaft 29 is rotatably supported by a bearing 37 which is provided with an inner surface 32 of the case 32. The base plate 20 to which the photo sensor 21 is attached is fixed on the inner surface 32 a of the case 32. As the second embodiment does not have the base plate 16 of the first embodiment, the structure of the second embodiment is simple.

[0045] Further, as shown in FIG. 7, the symbol display device 5 may have a case 32 for containing a reduction gear 31 which has no inner gear portion but is a plain gear. The reduction gear 31 and a connect member 33 are fixed to a rotary shaft 35, and when the reduction gear 31 rotates, the rotary shaft 35 and the connect member 33 rotate integrally. The connect member 33 has projections 33 a which is fitted and the reel 24 is fixed to the rotary shaft 35 with a screw 26. Further, a light-shielding fragment 34 is provided for the reduction gear 31 and detected by the photo sensor 21 in accordance with the rotation of the reduction gear 31.

[0046] In an embodiment illustrated in FIG. 8, the bearing 32 b is supported by a bearing holder plate 36. The bearing holder plate 36 is, as shown in FIG. 8A, constituted of a disk portion 36 a and a protruding portion 36 b formed with the disk portion 36 a. The disc portion 36 a has holes 36 c for inserting the screws 37 therein and an opening 36 d for inserting the protruding part 30 a of the stepping motor 30. In the protruding portion 36 b an opening 36 e is formed. The opening 36 e is fixedly fitted on the bearing 32 b. The bearing holder plate 36 is fixed with the screws 37 to the stepping motor 30 which is fixedly disposed on the inner surface 32 a of the case 32. Note that the bearing holder plate 36 may be fixed to the stepping motor 30 by welding and the like. Further, the bearing holder plate 36 may be disposed on a bottom of the stepping motor 30. Furthermore, on the inner surface 32 a of a bottom of the case 32, a protruding may be formed such that the protruding and the bearing holder plate 36 may support the bearing 32 b.

[0047] In FIG. 9, a small pulley 41 is attached to the drive shaft 14 of the stepping motor 30. The small pulley 41 is connected through a belt 43 to a large pulley 42 attached to the rotary shaft 35. When the stepping motor 30 is driven, the small pulley 41 is rotated. The rotation of the small pulley 41 is transmitted through the belt 43 to the large pulley 42, and then the reel 24 rotates. As the large pulley 42 has a larger diameter than the small pulley 41, the rotational velocity of the reel 24 is reduced in accordance with a ratio between radiuses of the large and small pulleys 41, 42. Note that in FIG. 8 the same structure as in FIG. 7 has the same number, and the explanations therefore are not made.

[0048] Further, the symbol display device of the present invention may be used in other game machine, for example a slot machine and the like.

[0049] Various changes and modifications are possible in the present invention and may be understood to be within the present invention. 

What is claimed is:
 1. An symbol display device having a reel on whose periphery plural symbols are arranged, a stepping motor for rotating a reel, a rotation transmitting mechanism for transmitting a rotation of said stepping motor to said reel, said rotation transmitting mechanism comprising: a first rotational member attached to said stepping motor; a second rotational member for rotating said reel, a diameter of said second rotational member being larger than that of said first rotating member such that a rotational velocity may be reduced; and a housing containing said stepping motor, said first rotating member and said second rotating member and rotatably holding said second rotational member, said housing being disposed in said reel.
 2. An symbol display device as claimed in claim 1, wherein said first rotational member is a drive gear, and said second rotational member is a reduction gear.
 3. An symbol display device as claimed in claim 2, further comprising: a partition plate for separating an inside of said housing, wherein said reduction gear is rotatably attached to said partition plate, a part of said reduction gear protrudes from an opening of said housing, and said reel is attached to said part.
 4. An symbol display device as claimed in claim 3, wherein said reduction gear has an inner gear portion meshed with said drive gear.
 5. A symbol display device as claimed in claim 2, further comprising: a rotational shaft, rotatably attached to said housing, for holding said reduction gear; and a connect member for holding said reel, said connect member being formed with said reduction gear.
 6. A symbol display device as claimed in claim 5, further comprising: a bearing for rotatably supporting said rotational shaft, an first end of said bearing being fixed to said housing; and a bearing holder plate having an opening that is fixed to said stepping motor, said opening being rigidly fitted to an second end of said bearing.
 7. A symbol display device as claimed in claim 2, wherein said first rotational member is a small pulley, said second rotational member is a large pulley, and said large pulley is connected through a belt with said small pulley.
 8. A symbol display device as claimed in claim 7, further comprising: a rotational shaft for holding said large pulley, said rotational shaft being rotatably attached to said housing; and a connect member for holding said reel, said connect member being fixed to said rotational shaft.
 9. A symbol display device as claimed in claim 1, further comprising: a light-shielding fragment attached to said second rotational member; a photo sensor fixed in said housing, said photo sensor detecting a passing of said light-shielding member in order to detect a home position of said reel. 